The invention is based on an electrical machine, preferably a rotary current generator or three-phase generator with a rectifier component.
In a known solution of the type mentioned above (U.S. Pat. No. 5,451,823), the positive and negative diodes of a rectifier component are each fastened to a cooling member or heat sink and electrically connected therewith by a connection. The heat sinks are fastened to the end face of an end shield for a rotary current generator so as to be sandwiched with an insulating plate added therebetween. The lower heat sink is attached to the end face of the end shield so as to be electrically and thermally conducting. A printed circuit board having a quantity of conductors embedded in the plastic of the printed circuit board for the connection of a positive diode and a negative diode on one side and having the winding ends of the rotary current winding in the stator of the rotary current generator on the other side is located on the upper heat sink. This rectifier component is held together by rivets and is fastened to the rotary current generator by screws. For purposes of cooling the upper curved heat sink, this heat sink is provided in the area of its inner circumference with a plurality of cooling slits which are arranged next to one another and oriented axially relative to the axis of the electrical machine; an axial cooling air flow is sucked in at the front side through the cooling slits from the outside toward a fan which is fastened to the rotor of the generator. The cooling air is blown radially outward through slits at the outer circumference of the end shield by fans in a known manner.
A disadvantage in this known solution is that the openings provided in the upper heat sink of the rectifier component for the flow of cooling air have relatively small cooling surfaces for dissipation of heat, so that a relatively thick upper heat sink is needed in order to achieve an adequate cooling surface at the cooling air openings. As a result of the accumulation of material required in this case, the upper heat sink used in this case is correspondingly expensive and heavy. Further, in order to achieve a large cooling surface for the cooling air flow, the openings in the heat sink are constructed as narrow, radially extending slits which again present a relatively high air resistance for the cooling air flow. The air volume sucked in through these slits and therefore also the cooling effect are accordingly small. The use of more powerful fans leads to higher costs and increased flow noise.
It is the aim of the present solution to improve the cooling performance by rearranging the rectifier component.